Active positioning system

ABSTRACT

The object of the present disclosure is an active positioning system for positioning at least one mobile device ( 100 ) by utilizing radio frequency technology, the positioning system comprising at least one essentially stationary fixed base station ( 101 ) i.e. an active positioning system antenna ( 101 ), and an electronics unit ( 106 ) i.e. a transceiver of the antenna ( 101 ), which transceiver comprises at least one antenna for transmitting signals comprising at least position information to at least one mobile device ( 100 ), which position information of the signals comprises information on an effect area of the antenna ( 102, 104 ) by using certain transmit power. The active positioning system comprises as the mobile device a TAG ( 100 ), which is fixed to the user or application of the TAG directly or indirectly, an electronics unit ( 106 ) of the base station ( 101 ), at least one antenna ( 102, 104 ) directed to different sections of a controlled area. The active positioning system antenna ( 101 ) receives said transmitted at least one signal of the formed measurement signals and information signals, and the positioning system antenna ( 101 ) comprises control means to control transmit power of said at least one antenna based on at least one signal of the formed measurement signals and information signals received at least by the base station for performing information processing of the mobile device position i.e. the TAG position at least based on transmit power level.

THE FIELD OF THE INVENTION

When different kinds of area specific positioning techniques develop,more and more useful applications are found.

STATE OF THE ART

On the market have been on sale RFID-antennas (Radio FrequencyIDentification), which limit a controlled area by RF (Radio Frequency)radiation pattern to a certain area, in which limited RF area arrivingmobile devices i.e. TAGs can be identified. The mobile device is bynature a RFID tag, which does not need a current consuming active frontamplifier in a RF receiver of the TAG as it operates in RF near fieldbased on passive signal detection not becoming active before it arrivesto an area of signal of sufficient strength, when it preferably andimmediately can measure directly the coming signal without a load of thefront amplifier, which load could be for example about 10 mA.

In this technology, such as access control applications, the problem hasbeen the fact that precisely in the location of the interior roof of thecontrolled building where the antenna would most advantageously locate,it is very often the lamp. In other words, the location of the lampwould be just the best antenna location or even the only good location.In addition, the problem is that the lamps are often metal from outsidei.e. from the sides, and thus they can easily distort the radiationpattern of the RFID antenna installed beside. Thus, the antenna shouldbe able, if necessary to replace the lamp when the antenna is to bepositioned to the place reserved by the lamp.

Another major problem, especially in the traditional RFID positioninghas been the fact that if is wanted positioning with exact limits in asmall space, taking into account movement direction, two antennas haveto be installed, which often require their own readers, and whoseradiation patterns interfere with each other without specialarrangements. Especially when broadcasting at the same time, theradiation patterns suffer from bad interferes. In narrow places theantennas often must be placed near metal structures, such as doorconstructions, or pipes, which also cause distortions to radiationpatterns, and for example at about 50 cm distance, can even destroy theradiation pattern.

Even if the antennas are fitted into a small space, signals are receivedfrom both antennas of the interface. In this case, without any specialarrangements, area changes all the time when new signals are receivedeven when being in place, unless the signals are measured and a TAGposition is evaluated on the basis of calculations and judgements ateach time point as in the patent application publication FI20095222 ispresented.

The problem to automatically send a location-based emergency call on thebasis of abnormal health status of a person for example in the case ofdownfall is that an accelerometer should in principle be measuring allthe time when a hit possibly indicating the downfall becomes until atthe end of the accelerating when the measurement is already too late. Onthe other hand, all downfalls due to worsened health status are notsudden, but a person can also be slowly and cautiously falling to thefloor, when the head begins to spin. On the other not only thehorizontal position could be used as an indicator, because thehorizontal position is also in normal situations, at least in bed.

BRIEF DESCRIPTION OF THE INVENTION

The object of the invention is an advanced antenna technology embodimentas one positioning cell of a positioning system, where antennas andradiators can be located to as good locations as possible and havingclose distances between them so that said close distance or other metalstructure causes no interferences in the positioning technology orneither simultaneous operation of the antennas or radiators causesinterferences in the positioning technology. This is achieved by anactive positioning system for positioning at least one mobile device byutilizing radio frequency technology, the positioning system comprisingat least one essentially stationary fixed base station i.e. an activepositioning system antenna, and an electronics unit i.e. a transceiverof the antenna, which transceiver comprises at least one antenna fortransmitting signals comprising at least position information to atleast one mobile device, which position information of the signalscomprises information on an effect area of the antenna by using certaintransmit power, which effect area of the antenna is dividable on two ormore sections based on power measurement, calculation and/or judging.The active positioning system comprises as the mobile device a TAG,which is fixed to the user or application of the TAG directly orindirectly, an electronics unit of the base station, at least oneantenna directed to different sections of a controlled area, and, ifnecessary, at least one external antenna to divide the controlled areato sections and to transmit additional information signals comprisingantenna specific limit and control values to the mobile device i.e. theTAG in addition to transmitting signals comprising position information,and said TAG comprises at least one antenna to receive said signals andadditional information signals transmitted by at least one antenna, andthe TAG comprises at least one electronics unit to form measurementsignals and information signals based on said signals and additionalinformation signals received by the antenna for performing informationprocessing of TAG position, and TAG comprises said at least one antennato transmit at least one of the formed measurement signals andinformation signals to the active positioning system, which comprisessaid base station to receive said transmitted at least one signal of theformed measurement signals and information signals, and the positioningsystem comprises control means to control transmit power of said atleast one antenna based on at least one signal of the formed measurementsignals and information signals received at least by the base stationfor performing information processing of the mobile device position i.e.the TAG position at least based on transmit power level.

The invention is based on time division of signals used in thepositioning and on dividing the controlled area to different parts andon functional effectivity in the co-operation of positioning systemtechnology such as antennas, radiators and the electronics units toutilize said time division and area division.

The benefit of the invention is so preferred relocation as possible ofantenna technology used for positioning as possible. According to theinvention is also compensated for successfully out the main sources oferror, which have been problems of prior art.

The active positioning system antenna according to the invention, i.e.the active antenna can also in one embodiment replace a lighting unit,which has been unfortunately located in buildings in just those placeswhere the placement of positioning system antenna is optimal.

For example, the positioning system antenna according to the inventionintegrated with efficient LED technology (Light Emitting Diode) lightingis feasible with so low current that a lamp can in power outagesituation, act as emergency exit lighting supplied by own battery orbatteries or supplied by some external certified current source orvoltage source.

According to the advanced antenna and tag technology according to theinvention can also improve the functionality of the prior art solutionin positioning, where the mobile device TAG sends a beacon signal andthe base stations measure the RSSI value of the incoming signal, and trycalculatively on system level to determine the location of the TAG.

The main benefit will be that the active antenna with several radiatorsis able to determine the direction where the signal comes from and cantogether with step measurement of TAG and with electronic compass-basedmeasurements define the TAG location without a base station network,which is required in conventional triangulation-based systems withoutremoving still the possibility to further improve the positioningaccuracy by co-operation of network of several active antennas utilizingfor example triangulation. Electronic compass solution of TAG enablesutilization of TAG attached to the user's body or clothing to detectposition of the user in at least three coordinates (x, y, z), whichfeature together with TAG informing the person being in bed based on,for example, the bed weight and/or on measurement of movement in thebed, at least together with positioning information provided by thesystem enables an automatic information transmission of an abnormalsituation in which a person is in a horizontal position outside of hisbed.

LIST OF FIGURES

FIG. 1 presents an application example in accordance with the invention,said example having two areas to be monitored.

FIG. 2 presents an example of construction of a complex andsophisticated implementation of the active positioning system antennaaccording to one exemplary embodiment of the invention, the figurehaving limitations of a two dimensional image.

FIG. 3 presents an example structure of a complex and sophisticatedimplementation of a TAG 100 according to an exemplary embodiment of theinvention.

DETAILED DESCRIPTION OF THE INVENTION

According to the implementation of the invention is carried outpositioning of at least one mobile unit, i.e. a TAG 100 in a positioningsystem area by an active positioning system antenna 101 utilizingRFID-technology (Radio Frequency IDentification) radio frequencytechnology in the region of the system according to the invention. Tagin this patent application does not necessarily mean any standardscompliant device or device part, but a device that is attached to amonitored, at least intermittently, moving and stationary target. As anantenna is used for example, a direction antenna 202 or a messagetraffic antenna to reception and/or broadcasting in RF frequencies. Whenan antenna has a name radiator 102, 104, it is then emphasized the factthat the radiator is used primarily to broadcast signals, but theradiator is, therefore, also the antenna, which can be used, whennecessary, for both signal transmission and reception tasks.

A very preferred solution when aiming to small size is to locate forexample an entity of two antennas 202 to the same casing so that twoseparate radiators 102, 104 performing corresponding function areinstalled to the same casing. In this case, the outer dimensions of thesolution are obtained to smallest possible levels, and manufacturabilityof the product is as simple as possible. Also the base stationelectronics 106 is then very preferably installed inside the sameantenna casing.

The active positioning system antenna 101 comprises a lightingarrangement integrated or attached to an electronics unit 106 of theantenna 101, said lighting unit being preferably accomplished by LEDtechnology 132, 134.

An active positioning system antenna, i.e. an active antenna 101 canreplace a lamp, which is interfering the antenna, and for example twoseparate antennas and the RFID-base station, enabling said RFID controlpackage for the installation of a very small space, and also situated inthe most preferred location area of area limitation and operability ofthe passage control. The active antenna 101 can also be in a high roomlowered to a suitable height with a wire of the antenna such as it canbe done with a normal lamp.

In demanding projects the active positioning system antenna 101comprises one or more antenna operating in time-divided manner attachedto the electronics unit 106 of the antenna 106 with an external cable toobtain essentially clear area distinction.

The active antenna 101 comprises one or more radiator 102,104, which isconnected to, or more preferably integrated into the electronics unit106. The radiators are connected most preferably to a common endamplifier time-divisionally so that the radiator, which is notconnected, represents a high impedance, at least with broadcastfrequencies, when said radiator is not radiating, i.e. transmitting.

The radiators are separated from the amplifiers by RF switches so thateach radiator in turn is in connection to own amplifier or to a commonend amplifier of the radiators. An area monitored by locating anddirecting one or more of the external antenna 202 and/or the radiators102, 104 is divided into one or more sub-areas, especially when it iswanted to distinguish essentially clearly these sub-areas from eachother.

The mobile device, i.e. the TAG 100 knows on the basis of RF signalstransmitted by one or more of the radiators, or by an external antenna,the area of the radiator or the antenna, which is involved at each timepoint. The active antenna 101 can through one or more external antenna202 and/or internal radiators 102, 104 send additional information toTAG, such as antenna and radiator specific control values on the basisof which the TAG will be better able to calculate and/or judge currentlocation. TAG 100 comprises at least one antenna 103 to performRF-transmission/reception tasks and and an electronics unit 110 formeasurement of said signals received and for processing on the basis ofadditional information received via the antenna and/or stored in itsmemory.

The positioning according to the invention is performed so that a mobiledevice, i.e. the TAG 100 in the interface receives via one or more ofthe antenna 202 and/or the radiator 102, 104 signals, the intensity ofwhich the mobile device self-measures and/or counts amount of saidsignals per time unit, and calculates and/or concludes by usingdifferent kind of algorithms on which area expressed by positioningsignal transmitting antennas or radiators the TAG 100 is at each timemoment. In this a crucial benefit is that the mobile device 100 itselfmeasures the signal strength and processes it mathematically andlogically so, that it is comparable to signals received by otherradiators and/or antennas. The interface is to be set and changed alsoprogrammatically. These matters enables the area interfacing to operatereliably in a very small space, since in this antenna and/or radiatorsignals may extend overlapping each other's areas.

The invention is based on the internal radiators 102, 104 of the activepostioning system antenna, i.e. the active antenna 101, directed atdifferent points of the monitored area and/or one or more of an externalantenna 202 cable connected to the active antenna electronics unit 106sends by using at least one radiator limit and adjusting values, whichare radiator specific comprising the additional information signals timedivisionally in addition to spatial information containing signals. Themobile device, i.e. the TAG 100 receives said signals sent by theexternal antenna and/or internal radiator to process locationinformation of said mobile device and to form measurement signals, whichmeasurement signals and/or the processed values of them the mobiledevice 100 may, when necessary, send to control means comprised by theactive positioning system antenna 101, when at least in the so-calledlearning situation radiating efficiency of the at least one of theradiator and/or the antenna is controlled situation specifically on thebasis of said measurement signals and/or processed values of them sothat the processing of mobile device location information is specifiedat least based on the level of radiating efficiency. At the same timecan be perform filtering and create on the basis of them parameters tobe send to the mobile device, to avoid error values existing in someawkward positioning coordinates caused by positioning signal distortionsin influencing the location information processing of the mobile device.

An processing part of the active positioning system antenna or activeantenna 101 memorizes at least in configuration and in learningsituations the values and parameters received by the TAG 100 andpossibly further processed values and parameters by the processing partas radiator 102, 104 specific values or in the case of an externalantenna 202 as antenna specific values, and sends this information asadditional information in addition to signals containing locationinformation to all other mobile devices 100 of the system at least whenthey move onto the area of said positioning cell.

In an implementation according to the invention external antennas 202and internal radiators 102, 104 are to be placed close to each other, asthey are, or at least some of them, time divisionally asynchronouslyworking, so that their fields do not interfere or even cancel each otherout. This time divisional is formed preferably by using an RF switcharrangement, when one and the same power amplifier is preferably used intransmission operation of several radiators or antennas.

However, the mere time divisional is not yet sufficient to allow normalstructured antennas 202 and radiators 102, 104 to be placed very closeto each other, because without special arrangements a very close secondantenna, or radiator causes radiation loss of first antenna, at least bydistorting the radiation pattern. Very close places mean in this forexample such places of antennas and radiators that the antennas witheach other or the radiators with each other or both the antennas andradiators with each other, each depending on the implementation, areplaced 2 mm-60 cm apart from each other. Transmission of antennas and/orradiators, which area placed very close to each other is important tohave different timings at least time divisionally, and in additionantennas and/or radiators which are not transmitting should verypreferably be electrically disconnected from the antenna or radiatorwhich is transmitting during the transmission time, in other wordsshould represent a very high impedance to the transmitting radiator 102,104 and to the antenna 202 being at close proximity, at least whenaiming at small outer dimensions of the entity. In this way, theantennas and/or radiators do not interfere each other's signals.

The specially designed radiators, such as the CAN antennas (English namecomes from a can-shape), is to be one application form of an activeantenna, in which can be achieved radiator specific directivity andwithout interfering each other with certain arrangements so that otherradiators need not to be electronically disconnected when one radiatoris transmitting, but at least outer dimensions of the solution becomelarge compared to the smaller radiator solutions who benefit from thedisconnections performed by the RF switches.

In the embodiment according to the invention is also achieved as asignificant advantage a low power consumption of the TAG 100, due to thefact that the TAG do not need a RF pre-amplifier. Indeed, in the priorart embodiment, when using the RF pre-amplifier, the power consumptionis easily up to 10 mA range. In the embodiment according to theinvention, the TAG is able to passively indicate a strong timedivisional signal of the active positioning system antenna 101, which isin practice an RFID base station with antennas, and the TAG is able towake up from sleep mode, when duration of the indicated signal exceeds apreset threshold, and then TAG begins to process the indicated signal.After this, the TAG will move back to sleep mode to wait for a newsignal. In one embodiment of the invention, the TAG waits for a signalto its movement indicator, after which the TAG 100 only allows awakeningto the positioning signal, or to start a positioning signal processing.

In the processing according to the invention a mobile device 100utilizes a motion sensor 153 to conserve power at least by stepmeasurement principle by rejecting repeated similar values when being ina place, or even by refusing to measure them at all, thus sparing energyin its battery.

FIG. 1 shows the invention in accordance with the implementation of anapplication example, where there are two monitored areas. There ispresented a doorway through which in the inner side of the “region1(permissible range),” can be moved freely, but as soon as transition tothe other side of the interface “Area2 (prohibited area),” sends themobile device, i.e. the TAG 100 automatically a notification of theborder crossing.

The active antenna electronics unit 106 may further comprise at leastone RFID transceiver with its processing units i.e. in practice realizethe use function of a base station comprising at least one radiator tosend signals containing at least location information to art least oneTAG. In this case is not required a separate base station, but all basestation operations are located in a same casing, i.e. in a package. Inthis case, one active antenna 101, which may comprise one or moreradiators 102, 104 operating time divisionally at different times, isable by itself, at least with more of the radiators, to perform aneffective area limitation in a very small area the same way as if itwere two separate antennas in different locations. This embodimentenables in addition one or more external antennas 202 to be connected tothe active antenna, which allows the positioning area for example to bewidened to cover effectively bigger passageway.

In RFID passage control is also beneficial to create also otherabilities to the active antenna electronics unit according to theinvention, such as perform on the monitored area measurements by aninfrared (PIR, Passive InfraRed), 133, 135 and/or ultrasound (US) motiondetector, and also/alternatively, if necessary, to use the IR (InfraReds) and/or ultrasound to communicate with TAG.

In this case, the active positioning system the antenna comprises of amotion detector combined to its electronics unit 106 externally of thecasing or internally of the casing, most preferably a motion detectioncomponent integrated to the same printed circuit board with theelectronics unit 106, the operation of which component is based onutilization of at least one of techniques for infrared technology PIR133, 135 and ultrasound technology and microwave technology, anddetection area of said component is most preferably overlapping with thearea limitation performed by the radiators 102, 104, the solution thensurely ensuring detection of non-permissed person on the detection areaon the basis that the person is not having a TAG 100, which wouldtransmit to the system a permissed access code and/or identificationinformation when entering the positioning area of the cell.

The active positioning system antenna 101 comprises at least datacommunication connection arrangement 121, 125 connected to itselectronics unit 106 and most preferably integrated to to the circuitboard to deliver data between the active positioning system antenna andthe outside world.

Thus to the same active antenna according to the invention is, whennecessary, preferably integrated voice and/or an IP connection to theoutside world, for example, by using at least one GSM/GPRS/3G/CDMA,WLAN/WiFi/WiMAX/Flash-OFDM/W-CDMA- to implement a module 125 and/orwired by using at least one of techniquesphone/modem/ISDN/ADSL/VOIP/USB/Ethernet to implement a module 121.

In this case, preferably is avoided problems caused by acousticfeedback, and in the loudspeaker 111 can, if necessary, be used highvolume levels, when the microphone 138 and the loudspeaker 111 are farapart from each others.

In some applications, the active antenna 101 is able to operate thewired communication with the outside world, by using one or more ofcommon Ethernet, RS-232, and for example, units and communicationprotocols in accordance with USB and RS485/422—x.0 standards for examplewhen joining a passage control system of a building. For this purposethe device comprises one or more wired telecommunication module 121 as aseparate and/or the equivalent electronics integrated directly to thecircuit board 127.

Both control means of the TAG 100 and the active antenna comprisepreferably programmable processor technology, such as PLC (ProgrammableLogic Controller), to carry out its measures, such as, for example, toform measurement signals in the TAG and to perform control operations ofradiating efficiency by the control means.

In the preferred embodiment of the invention the active antenna maycomprise at least one antenna, which is a separated antenna from theactual positioning system antennas, by which is carried out an RF signaltransmission and reception to other purpose of use than the positioning.This is carried out preferably in such a way that the transmission andreception can be mutually independent on their own frequency range.

The antenna is required in some applications only to other radiofrequency communication, because the RFID radiators can not receive welloutside of their radiation patterns because of their directivity. In onepreferred embodiment the antenna is connected or integrated theconnection cable 109 of the active antenna.

The active positioning system antenna can be placed in its mostpreferred location for example, so that it is accompanied by anintegrated lighting arrangement, in which case both, as well as alighting unit and the active positioning system antenna, may realizetheir use function in a preferred location, such as for example in alobby room of the building.

The active antenna comprises at least one RF switch available to each ofthe radiator, or an external antenna in turn and/or selectively at thesame time being connected to one or more power amplifier, and aremovable radiator 102, 104 of the isolation embodiment and/or anexternal antenna 202 to be galvanically so isolated that said radiator102 or external antenna 202 becomes a high impedance object in respectto one or more other radiator 104 and/or external antenna.

The RF switch electronics can be preferably implemented in one or moreintegrated circuit, each of which comprising one or more of the RFswitches.

The RF switch solution in the active antenna electronics unit 106, whichis used for connecting the radiators, can also be used for adjustingelectrical length of them and other parameters such as a reflectivity,and at least the ground level size and/or shape in order to changeactive antenna characteristics depending on the situation and timemoment needs so that transmission frequency and radiation pattern of theradiators can be altered so that operation of the solution suffersignificantly. For example, transmission frequency and directivity candiffer greatly from receivement frequency and directivity.

The active positioning system antenna may be developed in the preferredembodiment also in such a way that to the active antenna is connected orintegrated a motion detection component, which is preferably based onsimultaneous utilization of infrared technology PIR 133, 135 andultra-sound, or on utilization of at least one of them. Active antenna101 can also be connected to data communication connection arrangement121, 125 to deliver data between the active antenna and the outsideworld, i.e. other devices and/or data communication networks. Datacommunication connection arrangement to outside world can also beconnected to or integrated with other parts of the active antenna suchas for example the control means. The active antenna may also comprisemeans for sound reproduction and for at least two-way voice connection.As means for sound reproduction can be at least one of a speaker 111 anda microphone MIC 138, and at least one of said means can be located tothe mobile device, i.e. to the TAG 100, which has a telecommunicationslink to at least one antenna of the positioning system antenna 101, andthus possibly also to the outside world. For example, at least onemicrophone 139 may be located in a TAG locating in thetelecommunications link area, and be connected to at least one antennaof the positioning system antenna.

In the preferred embodiment of the invention can be utilized aconnection realized by articulated joints, by which connection thedirection radiator is connected to its electronics unit 106 to utilizesaid articulated joints in directing of the direction radiator 102, 104.The articulated joints 118 can be as simplest be freely bending stripmade from metal or from other suitable material, which connects theradiator module to the body structure of the casing formed by theelectronics unit 106, ground level or to the circuit board 127.

In addition that the multi-radiator solution achieves in the RF nearfield a good area selectivity, can the solution be used effectively inimproving the long-distance field positioning, so that the TAG 100itself sends a beacon signal after leaving the local field and theactive antenna measures from a signal it receives a RSSI (ReceivedSignal Strength Information) value by each of its radiators and/orantennas.

The active antenna is able to measure from the TAG 100 signal RSSI(Received Signal Strength Information) value by each of its radiators102.104, and/or antennas 202, and it gets the biggest measure from theradiator 102, 104 and/or the external antenna locating in the bestdirection as seen from the TAG 100 and from the others correspondinglysmaller measurement values in relation to value of angular deviation oftheir direction from the best direction.

For example, a solution of four radiators achieves a very highselectivity for the direction compared to normal solutions, where singleantenna cannot provide any information about the beacon (TAG 100)direction. In a preferred embodiment of the invention according todirection selectively a single radiator is structurally independentradiator module with directional antenna 102, 104 capabilities, in whichcase its radiation pattern has a good front/rear ratio (eg 10 dB) whenit receives the signal coming from behind at a 10 dB lower level thanthe signal coming directly from front.

TAG sends step detection as seldom as possible to minimize powerconsumption and most preferably also step measurement by utilizing forexample piezo motion detector 153. Most preferably the motion sensor iscarried out in connection with a shock sensor 151, in which case thecombination of the sensors is adjustable for different sensitivitysettings.

Step length of the distance travelled can be re-calibrated each timewhen a person passes through a near field comprising known dimensions,which are already being formed by an active cell of the active antenna.In this role, the active positioning system antenna to notifies the tagof the boundaries and/or the dimensions formed by the radiation field atleast based on radiation intensities of its radiators 102, 104, and ofany of its external antennas 202, 204, and if necessary, for example,utilizing data given by an IR or ultrasound radar. The method increasesafter the calibration measurement accuracy in assessment of distancetravelled by the TAG.

By this advanced step measurement method can in addition be betterassessed person's energy consumption, especially when also the person'sbody weight is known.

In one application of the system, in an electronics unit 110 of the TAG100, which sends beacon signal and performs step measurement ispreferably a an electronic compass solution 152 to measure direction oftravelling in addition to measure number of steps, when the positioningcan be performed even in a nearfield of a cell formed by a single activeantenna 101, when the TAGs direction of travelling is known when itexits from the near field of the positioning cell formed by the activeantenna 100, information of the compass direction and of the travelleddistance sent by the TAG 100 and strength information (RSSI) of thebeacon signal sent by the TAG 100, which is preferably obtained, whilethe TAG 100 sends said step measurement information and directioninformation.

TAG sends rarely its data and a beacon signal in order to minimize powerconsumption, only when its location changes significantly, or because ofany event recognized by its operation logic. The implementation ofelectronic compass 152 is most preferably based on an integrated circuitsolution, i.e. on an electronic compass circuit.

Positioning in a system based on one or more of the active antennas andTAG performing step and direction measurement can be further improved byplacing over the doors of lanes fixed installations versions of TAG 100of the system, type Door-TAG, which identifies for example, a distancechange of a magnet attached to a door in relation to the location of theTAG most simply based on a reed switch, or in a sophisticated versionthe magnetic field is measured by a sensor, which allows a greaterdetection range to place the TAG more freely. Said sensing element maypreferably be even the same sensor, by which the compass of the mobileTAG 100 is implemented.

Thus, the system receives the information of the room door which hasbeen opened in the hallway at the same time, while the TAG 100 is movingin said direction. Event detection logic is improved by the TAGinformation that stepping has stopped and/or that direction has changedat the same moment, when the door-TAG indicates the event. On the basisof said information the events can be logically combined by a very highprobability and do so quite reliably accurate positioning to the room inquestion. At the same time the system will automatically certifytracking information as RSSI measurement values from the TAG in saidroom without separate “site survey”-type system teaching, which has tobe made in the traditional systems when taking the system into use.

In addition, beacon signal measurement values obtained by the activeantenna can be statistically processed and over time can be detectedreadings on the basis of measurement values, which refer to saidperson's general places of location, including workplaces, bed, toilet,etc., that information can be used in the automatic learning of thesystem, still without a need for “site survey” type teaching. Additionalvalue to Door-TAG investment in a building is for example in a emergencycall application, when the same door-TAG indicates preferably, e.g. byvoice and sign light flashing above the door of the room where a personneeding assistance locates in the corridor after the person has calledhelp by his alarmTAG, making it easier and faster to get help.

The electronic compass solution 152 of TAG 100 allows utilization of aTAG 100 attached to the user body or clothing in at least threecoordinates (x, y, z), which feature together with information of TAGmeasurements of bed weight and/or of movements in the bed and at leasttogether with positioning information updated by the system implementsan automatic notification of an abnormal situation, where the user is ina horizontal position outside of his bed.

The TAG according to the invention is able to, in a particularapplication with the aid of an electronic compass 152 and a shock sensorby using suitable program algorithms, to detect, for example, that theperson carrying it falls down or other abnormal behaviour and is able toinform this by its radio part at least to the active antenna, which byits telecommunications means forwards this information withoutlimitations, by using wired or wireless communication. If necessary,detection accuracy of a fall down situation can be improved by use of anacceleration sensor of the electronic compass circuit, for example,AK8976A, acceleration sensor, or by use of a separate accelerationsensor, if the electronic compass circuit of the application is not ableto measure acceleration.

In a very preferred embodiment of the invention to detect fall downsituation use of the traditional “acceleration, followed by a hit, andhorizontal position” measurement procedure is even unnecessary, evenwhen as a condition for fall down notification is used only horizontalposition of the person and information that the person has left his bed.This ensures that a error alarm is not given when the person goesnormally to sleep in a horizontal position. Similarly, when a person tolies down, though very slowly, as in the case of sick incident canoccur, and the matter may be reported immediately at least as abnormalevent, in such as work safety or patient safety control relatedapplications.

In addition, the method related to identification of the horizontalposition forgives in energy budget of the battery of the TAG 100 theuser holds so that the acceleration measurement need not hurry withsituation processing, because for abnormal event indication issufficient that the person has left the bed and is in a horizontalposition.

The sequence of events is problematic for the use of accelerationsensor, because the triggering to the situation is only got from thehit, which wakes up the TAG to measure, when the acceleration sensorshould have been connected to measure already before the hit, whichmeans in principle, constantly, if it should be able to express such anevent. As IC technology advances, the power consumption problem ofacceleration measurement is diminishing, and with new circuit solutions,such as for example the Analog Devices ADXL346 chip can be up tocontinuously measure with power consumption, which according to themanufacturer is only 23 uA. It is then possible with one accelerationsensor, in addition to detect fall down situation, perform otherfunctions such as the identification of hit, which functions wouldotherwise require their own sensors for and programs. Also the stepmeasurement can be performed in the same circuit, such as by theabove-mentioned Analog Devices ADXL346.

For the detection of fall down the TAG should be attached to the body,such as e.g. pulse counter, so that the horizontal position of the bodycan be indicated with certainty. Also with an appropriate way toclothing or headgear attached TAG 100 is able to indicate the positionof the body and depending on the application the alarm can beconditioned to avoid error alarm with other measurement or feedbackdata, such as the person is not moving, or is passive, or lack ofresponse to such as loud generated by a TAG piezo membrane 151, or togenerate vibrations from a vibration element which is familiar from themobile phone. In this bed control task is a preferred TAG 100 embodimentof the invention, a bed-TAG_1 100, where the hit sensor 151 of FIG. 3 isreplaced by a weight measuring sensor, such as resistive orpiezoelectric, which TAG 100 is located under leg of person's bed, whenthe TAG will indicate when a person has left the out of bed by observingintelligently, at least the weight of the bed, and by comparing thereadings to a situation where the location of the person is reported tobe far away from the bed. Said weight measurement by the TAG is able toadapt to reasonable weight changes in conditions of varying loads as aresult of its intelligence and accuracy in positioning, when gravitypoint of the bed changes.

The TAG may also send information about the person's movement in bedduring the night, for example on the basis of signals from apiezoelectric movement sensor 153 located in the same unit, if the TAG'sweight/pressure-measuring sensor 151 is unable to adequate sensitivity.

A preferred bed-TAG versio2 may be nearly the same as normal TAG 100according to the invention, which needs to have only sensitive motionsensor, for example, piezoelectric, when it for example below amattress, indicates and identifies motion and/or pressure against themattress, said data together with positioning information is sufficientto guarantee a reliable indication of the bed conditions. To the tag canalso be attached a bed sensor, for example Emfit Bed Sensor, which isnormally located under the mattress and commonly available.

At best, the TAG may send the collected kinetic measurement data as timeseries, for example, in one or more package in RF at specified timeintervals to minimize power consumption, in which case the receivingactive antenna can transmit the data for example to PC, where it can beviewed as a graphic activity curve also through a browser and remotely.

The drawing of the activity curve continues, if necessary, as when theperson is away from the bed the carried TAG 100 operating the same wayas the bed-TAG 100, at least based on the measurement results of themotion detector, By this way drawing of the activity curve can operatearound the clock, even if the person took off the carried TAG.

The mobile TAG can also store measurement information during the daywhile being out of reach of the active antenna and process the storedmeasurement data when re-entering the range area.

Since for the detection of fall down the TAG 100 is already attached tothe body, e.g. such as pulse counters, it can also be convenientlymeasure by heart rate by its motion detector, which information it cansend for example to pulse counter wrist with an appropriate protocol inaddition to that heart rate data is sent with other information to theactive antenna. Pulse is obtained as activity curve and the curve ofenergy consumption in the corresponding graph, to eg a PC or most simplyas a numerical figure to the active antenna 101 connected is playdevice.

Energy consumption can be estimated fairly accurately, when the heartrate, distance/pace and the person's weight is known, which weight canbe measured if desired automatically by bed sensors, by installing underall legs of the bed corresponding tags, and on the basis of reportedmeasurement values from said tags for example the mobile TAG 100, or theactive antenna 101 can calculate a common weight of the person and thebed and reduce the weight of the bed, which can be measured when thepositioning notifies the person to be far away from the bed. By this tagsolution can be implemented even up to a passive observation of person'sweight variation and a person's weight curve can be representedgraphically in a time domain with other curves which function is ofsignificant benefit for example in monitoring effects of medicationdispensing in a person being in diuretic medication.

As additional information on verifying the person being in the bed, theactive antenna can utilize the automatically learned locationinformation of the bed, which information together with weighing of thebed significantly makes faster to give an automatic alert of thecertified so called real fall down situation outside of the bed whencompared to traditional solutions, in which have to be waited for anunreasonable long time analyzing the situation to continue, before isenough courage to report due to fear of false alarms.

A localised fall down event can also be notified when the TAG 100 isoutside the active antennas 101 RF range, for example outdoors, when tothe tag according the invention is integrated at least the GPSelectronics part 155 and, alternatively, either the general wirelesscommunication electronics part with for example a GPRS-compatibleprotocol implemented module 156 or the person has a cell phone, forexample, with a Bluetooth readiness and installed such as a Javaapplication, which will discuss with the TAG via Bluetooth.

One version of the active TAG 100 can also be integrated inside a mobilephone or other portable device so that it informs the phone of itslocation indoors out of reach of the GPS at the same time allowing forthe fact that the phone turns the GPS on, only outdoors, whatinformation will enable significant energy savings of phone powerconsumption, especially if you are mostly indoors.

Such a version of tag that is enabled to operate even independentlywithout an active antenna, with the bed sensor together, but expressingan exit to outdoors is then depended on the RF range of the mobile TAGand the bed-TAG, which range is inaccurate.

When to the tag 100 is yet added the mentioned electronic compass basedon the earth's magnetic field to measure direction of travel, can evenonly on near field of cell formed by one active antenna 101 be carriedout positioning on the basis of information thus obtained, when is knownthe distance, direction and the beacon signal strength sent by the TAG.TAG sends a beacon signal with the above-mentioned data and receives, ifnot immediately, then next time, from the active antenna new data basedat least on said measurements on the RF receivement direction, and ifnecessary, also information about a larger entity. Most simply the TAG100 may inform its location change in the beacon signal, for example,the travelled distance as subdistances and the direction every time thedirection changes, starting from the last active 101 antenna and/or fromthe point mentioned in message before last message each time the traveldirection meet a deviation which is bigger than a set threshold, or atspecified time intervals by storing information in order to minimizepower consumption, and by sending the information at mentioned timeintervals, eg once every 20 seconds, as a sequence, which consists of aseries of successive measurements.

In a larger entity comprised of several active antennas 101 can alsotake advantage of triangulation and mathematical algorithms in trackingof more accurate location of TAG 100 on the basis of a RSSI value of thebeacon signal sent by the TAG 100, and at the same time utilizing in themeasurement accuracy significantly for each individual active antenna's101 good direction selectivity and in further accurated locationdetermination in addition to step measurement information/directioninformation sent by the TAG 100 with the beacon signal.

In outdoor positioning active antennas are needed, for example about onekilometre spaced network whose components can also be active antennasplaced in private residences, or in service residences, and then can bepreferably constituted a very extensive positioning area by the TAGswhose power consumption is minimal for example compared to GPSpositioning using solutions.

Active antenna or some other system preferably updates and refines asreturn data to the tag its self-maintained location information such ascoordinates, vectors and/or area knowledge, which informationpresentation form depends on the application and on the system way andrequired accuracy to perceive location for example on map presented onPC's display or on alphanumeric corridor screen.

Tag will be able to inform in addition to its user-id also its location,for example, in emergency call situation, the person calling for help bypressing a button 150, or by hitting a hit sensor 151 associated withthe TAG, which sensor can be adjusted to the appropriate sensitivitydepending on the application. The hit sensor principle to trigger thealarm allows locating the TAG under clothing, for example, because forthe hit accuracy of the hand it is sufficient that the tag gets a hitstrong enough, which differs from the normal operation.

At least the location of the push button 150 and the hit sensor 151, aswell as the location of a microphone, and other electronics, may varydepending on application in different parts of the circuit board beingdifferent from that presented in FIG. 3.

To the tag according to the invention can be attached, or morepreferably integrated a GPS electronics part 155 for outdoor positioningas well as the common wireless communication electronics component forexample implemented as a GPRS-compatible protocol module 156 or asintegrated to circuit board, which the device can indicate its locationout of reach of the active antenna such as on outdoor areas and stillperform with very low power consumption of most of the time because theactive antenna being in exit of the building, the TAG knows that the GPSis turned on only outdoors, and for example, GPRS only when it is neededto connect to. This allows a very compact implementation of the mobiledevice, at least of the size of the batteries, because many outdoor-useapplications have normally very short periods of operating time.

At least half-duplex voice communication can be implemented using a GPRSconnection very cheaply, as for example a hit sensor 151 based on apiezoelectric audio element is connected to GPRS 156 audio terminal inthe same switching solution, as the microphone 139 is disconnected fromother electronics and is connected to GPRS 156 audio input for the timeof voice communication. When aiming at improved sound quality, insteadof the audio element can be connected an actual loudspeaker solution.

In a preferred form, instead of the separate antennas, TAG 100 RFIDelectronic and/or GPS electronics 155 and the common wirelesscommunication electronics 156 use a common antenna 103, the electricallength of which is changed for each frequency suitable for the usepurpose, for example, with the same RF switch solution, which is usedfor the active antenna electronics unit 106 in connection of theradiators. In some applications, the common wireless communicationelectronic unit 156 is replaced by the Blue tooth electronics, throughwhich the TAG discusses with such as a mobile phone, allowing TAG powerconsumption and size reduction compared to a scenario in which the TAGconsists of electronics such as GPRS.

According to the same principle the TAG 100 may change the electricallength of its antenna when operating in other frequency bands as theRFID-band signalling of the active antenna 101. Thus the actual datacommunication between the TAG and the active antenna 101 in the longdistance field, for example FSK signalling, can operate at a completelydifferent frequency range than RFID positioning.

Active antenna wireless communication module 125 may also be a WLAN basestation, when the active antenna can thus replace the WLAN base station.Outdoor positioning can be also performed with the active antennasolution preferably in such a way that is formed large monitored area bya network of several active antennas, so that at least on the area edgesare placed the active antennas 10, which are targeted to receive abeacon signal sent by the TAG 100, the measurement values obtained fromthe beacon signal each active antenna transmits, e.g. by radio link tothe central computing unit, which can be for example a PC, which on thebasis of mathematical algorithms calculates locations of tags moving onthe area, and which location information is available from the server inreal time, for example, by using a web browser for example whensearching for a missing person. This network can be formed easily alsoin such a way that active antennas are placed to main buildings on thearea providing services, which together with active antennas locating inhomes can realize even without special arrangements a quite widepositioning network.

In outdoors positioning distances can reach up to a kilometre away fromthe active antenna, when the location of the antenna is high enough, andan appropriate radio frequency band is selected, as well as the TAGbeacon signal is to be sent using adequate transmission power when theTAG is moved to the outdoors.

In the text and claims the electronics unit components presented asmodules, such as the wired communications module 121, can in someapplications be also highly integrated to the printed circuit board, andwould therefore not necessarily be as individual units, as illustratedin FIG. 2, in which most of the actuators and electronics parts neededin different variations of the invention are presented in forms ofmodules. It is also to be noted that the modules and components in FIG.2 are generally not located in real places for the reason that a figuremust be presented in a patent application in a two-dimensional form.Control logic, control parts and processing parts are usually sodistributed and located on the circuit board 127 of the electronics unit106, that they cannot be presented as separate modules.

The RF amplifier/connector part located in the electronics unit 106 ofthe invention presented in FIG. 2 may be in some embodiment of theinvention entirely separate sub-module, so that it can be cheaply noiseprotected, for example by a metallic cover. The same also applies toparts of the electronics units of the invention in the tag 100.

The division to near field and far field presented in this documentrefers to the fact that in the near field RF signal reception anddetection performed by the TAG 100 is possible directly without apre-amplifier, for example with a diode detector. In the far field isrequired, at least, a preamplifier, and to a long distance it has to beadded at least one amplifier stage. That is why it makes sense that farfield measurement is performed by base station electronics 106 on thebasis of beacon signal sent by the TAG100.

Although the invention has been presented in reference to the attachedfigures and specification, the invention is by no means limited to thoseas the invention is subject to variations within the scope allowed forby the claims according to different kind of applications.

1. An active positioning system for positioning at least one mobiledevice (100) by utilizing radio frequency technology, the positioningsystem comprising at least one essentially stationary fixed base station(101) i.e. an active positioning system antenna (101), and anelectronics unit (106) i.e. a transceiver of the antenna (101), whichtransceiver comprises at least one antenna for transmitting signalscomprising at least position information to at least one mobile device(100), which position information of the signals comprises informationon an effect area of the antenna (102, 104) by using certain transmitpower, which effect area of the antenna is dividable on two or moresections based on power measurement, calculation and/or judging,characterized by that the active positioning system comprises as themobile device a TAG (100), which is fixed to the user or application ofthe TAG directly or indirectly, an electronics unit (106) of the basestation (101), at least one antenna (102, 104) directed to differentsections of a controlled area, and, if necessary, at least one externalantenna (202, 204) to divide the controlled area to sections and totransmit additional information signals comprising antenna specificlimit and control values to the mobile device (100) i.e. the TAG inaddition to transmitting signals comprising position information, andsaid TAG (100) comprises at least one antenna (103) to receive saidsignals and additional information signals transmitted by at least oneantenna (102, 104, 202, 204), and the TAG comprises at least oneelectronics unit (110) to form measurement signals and informationsignals based on said signals and additional information signalsreceived by the antenna (103) for performing information processing ofTAG (100) position, and TAG comprises said at least one antenna (103) totransmit at least one of the formed measurement signals and informationsignals to the active positioning system, which comprises said basestation (101) to receive said transmitted at least one signal of theformed measurement signals and information signals, and the positioningsystem comprises control means to control transmit power of said atleast one antenna (102, 104, 202, 204) based on at least one signal ofthe formed measurement signals and information signals received at leastby the base station for performing information processing of the mobiledevice position i.e. the TAG (100) position at least based on transmitpower level.
 2. An active positioning system in accordance to claim 1,characterized by, that the active positioning system antenna (101)comprises an outside or inside motion detector in a device casingconnected to the electronics unit (106) of the antenna (101), andoperation of the motion detector being based on utilization of at leastone of the techniques infrared technique PIR (133, 135), ultrasoundtechnique and micro wave technique, and detection area of the motiondetector being essentially overlapping with area limitation made by theantennas (102, 104).
 3. An active positioning system in accordance toclaim 1, characterized by, that the active positioning system antenna(101) comprises a telecommunication connection arrangement (121, 125),which is attached by integrating to a printed circuit board of theelectronics unit (106) of the active positioning system antenna (101) todeliver data between the active positioning arrangement and the outsideworld.
 4. An active positioning system in accordance to claim 1,characterized by, that the active positioning system comprises at leastone loudspeaker (111) and at least one microphone (138) as means toperform sound reproduction and at least bidirectional talkingconnection, and said microphone disconnects automatically when a radiomicrophone (139) of the TAG (100) switches on.
 5. An active positioningsystem in accordance to claim 1, characterized by, that the activepositioning system comprises at least one RF-switch to switch eachactive antenna in turn and/or selectable on one or more end amplifieressentially simultaneously, and an isolation arrangement to isolate adetachable internal antenna (102, 104) and/or external antenna (201,204) electrically so that said internal antenna (102, 104) and/orexternal antenna (202, 204) becomes an electrically high impedanceobject to one or more other internal antenna (102, 104).
 6. An activepositioning system in accordance to claim 1 or 5, characterized by, thatthe active positioning system is arranged to measure a RSSI (ReceivedSignal Strength Information) value from a dispatch of the TAG (100) byeach internal antenna (102, 104) of the system and/or by each externalantenna (202, 204) of the system to measure the highest measure valuefrom the internal antenna (102, 104) and/or the external antenna (202,204), which locates in the most preferred direction towards the TAG(100), and respectively lower measurement values from the others in afunction of angle deviation from the most preferred direction.
 7. Anactive positioning system in accordance to claim 1, 5 or 6,characterized by, that the TAG (100) transmitting beacon signal andperforming step measuring comprises in the electronics unit (110) of theTAG an electronics compass application (152) based on magnetic field ofthe Earth to measure direction of movement in addition to measure numberof steps to perform positioning on a neighbouring area of one or morecell formed by one or more active positioning system antenna (101), whenthe movement direction of the TAG (100) is known as it exits from theneighbouring area of said positioning cell formed by the activepositioning system antenna (101), information on the compass directionand the movement distance transmitted by the TAG (100), and informationon the strength (RSSI, Received Signal Strength Information) of thebeacon signal transmitted by the TAG (100), which strength informationis obtained essentially simultaneously with said step measurementinformation and direction information transmitted by the TAG (100). 8.An active positioning system in accordance to claim 7, characterized by,that the TAG (100) attached to the body or clothes of the user isutilized to detect alignment of the user at least in three coordinates(x, y, z) based on the electronics compass application (152) of the TAG(100), which feature together with information obtained from a TAG (100)measuring weight of a bed and/or movements in the bed, and at leasttogether with position information maintained by the system transmitsautomatically information on the abnormal situation, in which the useris in horizontal alignment outside the bed.
 9. An active positioningsystem in accordance to claim 1, characterized by, that the activepositioning system antenna (101) comprises LED lighting arrangement(132, 134) integrated or attached to the electronics unit (106) of theantenna (101) to replace, when needed, a lamp, which before took thepreferred location instead of the positioning system.